Fig. 1: Bioinformatic analysis of SscLLs.

a Amino acid sequences alignment of seven SscLLs. Black shadows represent the same residues, and gray shadows represent similar residues. The carbohydrate-binding motifs QPD and WSD are marked with red boxes, and the conserved cysteine residues that formed two pairs of disulfide bonds are shown in blue boxes. b Phylogenetic analysis of ladderlectins from various teleost fish. SscLLs were marked by red shadows, the accession numbers of ladderlectins from other species were shown in the pictures, and the numbers next to the internal branches indicate the bootstrap values based on 1000 replications. The color of branches represents the tissue expression specificity of ladderlectins, orange—testis, green—gill, blue—intestine, and black—other tissues. c Schematic of protein motifs of SscLL3604, which is the only one that does not contain a signal peptide. d Schematic of protein motifs of other SscLLs, with the signal peptide represented by an orange rectangle, and the lectin domain indicated with a rounded rectangle. e Tertiary structure of SscLLs. The signal peptides are shown with the stick model, the carbohydrate-binding motifs are shown with the spheres model, and the rest are shown with the cartoon model. Blue indicates α-helix, red indicates β-sheet, and random coil is marked with purple.